Self-propelled heavy duty mobile crane

ABSTRACT

A large self-propelled heavy duty mobile crane comprises a triangular support frame having a pair of spaced apart drivable steerable double bogies at its wide front end and a pair of spaced apart drivable steerable single bogies at its narrow rear end. The pair of front bogies are connected by an adjustable telescopic tie rod which maintains them either parallel or inwardly-toed, depending on the type of crane traverse and steering motion desired. A vertically swingable A-frame boom has its two spaced apart lower ends pivotally connected to the wide front end of the support frame directly above the attachment points of the front bogies to concentrate the load thereat. A vertically swingable inverted U-frame boom support mast has its two spaced apart lower ends pivotally connected to the wide front end of the support frame as close as possible to the boom attachment points.

United States Patent 11 1 Greenlay et a1.

[ Feb. 25, 1975 [75] Inventors: Roy Greenlay, Greenfield; George S.

Allin, Jr., Brookfield, both of Wis.

[73] Assignee: Harnischfeger Corporation,

Milwaukee, Wis.

[22] Filed: Nov. 23, 1973 [21] Appl. No.: 418,679

[52] U.S. Cl 212/8 R, 212/48, 280/792 C [51] Int. Cl. B66c 23/36 [58] Field of Search 212/8 R, 8 A, 9, 46, 48,

[56] References Cited UNITED STATES PATENTS 1,450,882 4/1923 Beckwith 212/49 2,096,186 10/1937 Tourneau 212/8 R 3,490,555 1/1970 Noack 180/792 C 3,532,178 10/1970 Lindbom ISO/79.2 C 3,545,627 12/1970 Letourneau... 212/145 3,638,805 2/1972 Garnier 212/145 3,684,044 8/1972 Watson 180/946 3,747,718 7/1973 Gauchet 180/946 FOREIGN PATENTS OR APPLICATIONS 6,405,689 11/1965 Netherlands...... 212/49 OTHER PUBLICATIONS Sky Horse Counter Balancing Crane/by American Hoist & Derrick Co. Dec. 9, 1971.

Primary Examiner-Robert J. Spar Assistant Examiner-Lawrence J. Oresky Attorney, Agent, or Firm-James E. Nilles 57 ABSTRACT A large self-propelled heavy duty mobile crane comprises a triangular support frame having a pair of spaced apart drivable steerable double bogies at its wide front end and a pair of spaced apart drivable steerable single bogies at its narrow rear end. The pair of front bogies are connected by an adjustable telescopic tie rod which maintains them either parallel or inwardly-toed, depending on the type of crane traverse and steering motion desired. A vertically swingable A-frame boom has its two spaced apart lower ends pivotally connected to the wide front end of the support frame directly above the attachment points of the front bogies to concentrate the load thereat. A vertically swingable inverted U-frame boom support mast has its two spaced apart lower ends pivotally connected to the wide front end of the support frame as close as possible to the boom attachment points.

11 Claims, 29 Drawing Figures PATENTEDFEB25I9Y5 3.868.022

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1. A self-propelled mobile crane comprising: a substantially triangular support frame having one end wider than an opposite end; spaced apart drivable and steerable first bogie means connected at spaced apart bogie connection points near said one end of said support frame; second drivable and steerable second bogie means connected near an opposite end of said support frame; driving means and steering means for said first and second bogie means; a vertically swingable room having a pair of spaced apart lower ends mounted for vertical swinging movement on said support frame, each boom end being pivotally attached to said support frame at a boom attachment point adjacent one of said bogie connection points; and a boom support mast having a pair of spaced apart lower ends mounted for vertical swinging movement on said support frame, each mast end being attached to said support frame at a mast attachment point adjacent one of said bogie connection points, said boom and mast attachment points being located substantially directly above said connection points of said frist bogies.
 2. A self-propelled mobile crane comprising: a triangular support frame having a wide front end and a narrow rear end and a transverse beam attached at said narrow end; a pair of drivable and steerable front bogies connected to said frame at spaced apart connection points near the corners of said wide front end of said frame; a pair of drivable and steerable rear bogies mounted at opposite ends of said transverse beam; driving means and steering means for said front and rear bogies; and adjustable telescopic tie rod connected to and between said pair of front bogies to maintain them in specific relationship with each other for steering purposes; means for locking said tie rod in extended or retracted positions; a vertically swingable boom having two spaced apart lower ends pivotally connected to said front end of said support frame at boom attachment points above said connection points of said front bogies to concentrate a load thereat; and a boom support mast having its lower end connected to said front end of said support frame adjacent a line between said boom attachment points.
 3. A crane according to claim 2 wherein said boom support mast comprises two spaced apart lower ends pivotally attached to said frame at mast attachment points adjacent said boom attachment points.
 4. A self-propelled mobile crane comprising: a support frame having a center of rotation; a first pair of drivable and steerable bogies connected at spaced apart connection points near one end of said frame; each bogie in said first pair having a center of rotation; a second pair of drivable and steerable bogies connected at spaced apart connection points near another end of said frame; driving means for said first and second pairs of bogies; and adjustable telescopic tie rod connected to and between said first pair of bogies to maintain them in specific relationship with respect to each other for steering purposes; means for locking said tie rod in extended or retracted positions; a vertically swingable boom having two spaced apart lower ends pivotally attached to said frame at boom attachment points substantially directly above said connection points of said first pair of bogies; a boom support mast having its lower end attached to said frame adjacent a line between said boom attachment points, and steering means for said first and second pairs of bogies to enable said crane to be steered for rotation either about the center of rotation of said crane or about a center of rotation between said bogies in said first pair.
 5. A selF-propelled mobile crane comprising: a triangular support frame having a center of rotation and having a wide front end and a narrow rear end and a transverse beam attached at said narrow end; a pair of drivable and steerable front bogies connected to said frame at spaced apart points near the corners of said wide front end of said frame; each front bogies being a double bogie and comprising two independently drivable bogie untis; a center of rotation between said front double bogies; a pair of drivable and steerable rear bogies mounted at opposite ends of said transverse beam, each rear bogie being a single bogie and comprising one independently drivable bogie unit; and adjustable telescopic tie rod connected to and between said pair of front bogies to maintain them in specific relationship with each other; means for locking said tie rod in extended or retracted position; a vertically swingable boom having two spaced apart lower ends pivotally connected to said front end of said support frame at boom attachment points above said connection points of said front bogies to concentrate a load thereat; a boom support mast having its lower end connected to said front end of said support frame adjacent a line between said boom attachment points; and steering means and drive means for said front and rear bogies to enable said crane to be steered conventionally or for rotation either about the center of rotation of said crane or about said center of rotation between said front double bogies.
 6. A crane according to claim 5 wherein said boom support mast comprises two spaced apart lower ends pivotally attached to said frame at mast attachment points adjacent said boom attachment points.
 7. A self-propelled mobile crane comprising: a support frame having a center of rotation on a longitudinal center line of said crane; a first pair of drivable and steerable bogies connected at spaced apart connection points near one end of said frame; a center of rotation between said first pair of bogies; a second pair of drivable and steerable bogies connected at spaced apart connection points near another end of said frame; and adjustable telescopic tie rod connected to and between said first pair of bogies to maintain them in specific relationship with respect to each other for steering purposes, said tie rod being movable between extended and retracted positions in response to outward and inward steering of said first bogies; remotely operable means for releasably locking said tie rod in either position; a vertically swingable boom having two spaced apart lower ends pivotally attached to said frame at boom attachment points adjacent said connection points of said first pair of bogies; a boom support mast having its lower end attached to said frame adjacent a line between said boom attachment points; steering means for said first and second pairs of bogies; and propulsion means for said first and second pairs of bogies; said crane being steerable conventionally by operation of said steering means to steer both of said bogies in said first pair simultaneously in the same direction and to maintain both said bogies in said second pair parallel to each other and parallel to said longitudinal axis of said crane while all said bogies are driven in the same direction by said propulsion means; said crane being steerable about its center of rotation by operation of said steering means to steer said bogies in said first pair inwardly with respect to each other and to steer said bogies in said second pair outwardly with respect to each other and by operation of said propulsion means to drive said bogies in said first pair in opposite directions with respect to each other and to drive said bogies in said second pair in opposite directions with respect to each other; and said crane being steerable about said center of rotation between said bogies in said first pair by operation of said steering means to maintain both bogies in said first pair parallel to each other and parallel to said longItudinal axis of said crane and to steer said bogies in said second pair outwardly with respect to each other and by operation of said propulsion means to drive said bogies in said first pair in opposite directions with respect to each other and to drive said bogies in said second pair in opposite directions with respect to each other.
 8. A crane according to claim 7 wherein said steering means comprises an individual hydraulic steering motor for each bogie and hydraulic means for operating said hydraulic steering motors and an individual propulsion motor for each bogie and means for operating said propulsion motor.
 9. A crane according to claim 8 wherein said remotely operable means is hydraulically operated.
 10. A crane according to claim 7 wherein each first bogie is a double bogie comprising two independently drivable bogie units and wherein each rear bogie is a single bogie comprising one independently drivable bogie unit.
 11. A crane according to claim 1 including an adjustable telescopic tie rod connected to and between said first spaced apart bogie means to maintain them in specific relationship with respect to each other for steering purposes and means for locking said tie rod in extended or retracted positions. 